1. Import deodorant.
2. Use deodorant.
Being in Japan, I've had people tell me I smell good. I get it a lot from students, actually. Now I'm not denying the fact - I do smell like a fresh field of (manly) flowers on a brisk spring morning, but I get complimented a lot more on it here than back home. I've also noticed foreigner friends of mine receiving the same kind words. Why is that?
I think it's because of the pitiful status of the Japanese deodorant market. According to Japan Market Intelligence, either the Japanese place less emphasis on smelling fragrant, or they don't believe they smell as pungent as us Westerners. I've actually heard that claim from foreigners before - that Japanese people don't smell. I've also heard that Japanese don't sweat. I'm not going to argue racial biology/anatomy here -that's not my strong suit; but I've taught enough high school kids here to know that Japanese people do sweat and they can smell.
I will say this, though - they do a good job masking both. People over here all carry around little clothes or handkerchiefs that they use to clean their faces when they sweat. And for all the public transportation I've utilized, I haven't encountered many bad cases of BO. So generally I tend to think of Japanese people as smell-less.
If you're looking to smell nice, however, your options are limited. There are really only two types of deodorant you can get here: crappy roll-on and crappy spray. I've tried both, and using them seriously doesn't appear any different from dabbing some antiseptic under your arm. They smell suspiciously like rubbing alcohol and whatever protection they afford gets smacked down by the brutal force of the Japanese summer. Alternatively you could go with Axe body spray, which they do have here, or some cologne. But neither of those are anti-perspirant, are they?
So yes, Japan, I do smell good. What's my secret? Real deodorant.